<template>
    <div class="list" ref="wrapper">
        <div>
            <div class="area">
                <div class="title border-topbottom">当前城市</div>
                <div class="button-list">
                    <div class="button-wrapper">
                        <div class="button">{{currentCity}}</div>
                    </div>
                </div>
            </div>
            <div class="area">
                <div class="title border-topbottom">热门城市</div>
                <div class="button-list">
                    <div
                        class="button-wrapper" 
                        v-for="item of hotCities" 
                        :key="item.id"
                        @click="handleCityClick(item.name)"
                    >
                        <div class="button">{{item.name}}</div>
                    </div>
                </div>
            </div>
            <div
                class="area" 
                v-for="(item,key) of cities" 
                :key="key" 
                :ref="key"
            >
                <div class="title border-topbottom">{{key}}</div>
                <div 
                    class="item-list" 
                    v-for="innerItem of item" 
                    :key="innerItem.id"
                    @click="handleCityClick(innerItem.name)"
                >
                    <div class="item border-bottom">{{innerItem.name}}</div>
                </div>
            </div>
        </div>
    </div>
</template>

<script>
import Bscroll from 'better-scroll'
import { mapState,mapMutations } from 'vuex'

export default {
    name:'CityList',
    props:{
        cities:Object,
        hotCities:Array,
        letter:String
    },
    computed:{
        ...mapState({
            currentCity:'city'  // 把vuex的公用数据city映射到这个组件的计算属性里，映射过来的名字叫currentCity
        })
    },
    mounted() {
        this.scroll=new Bscroll(this.$refs.wrapper)
    },
    methods:{
        handleCityClick (city) {
            this.changeCity(city)
            this.$router.push('/')
        },
        ...mapMutations(['changeCity'])
        // 有一个mutation叫changeCity,然后把mutation映射到这个组件里名字叫changeCity的方法里
    },
    watch:{
        letter () {
            if(this.letter) {
                const element=this.$refs[this.letter][0]
                this.scroll.scrollToElement(element)
            }
        }
    }
}
</script>

<style lang="stylus" scoped>
    @import '~style/varibles.styl'

    .border-topbottom
      &:before
        border-color #ccc
      &:after
        border-color #ccc
    .border-bottom
      &:before
        border-color #ccc
    .list
        overflow hidden
        position absolute
        top 1.58rem
        left 0
        right 0
        bottom 0
        .title
            line-height .54rem
            background #eee
            padding-left .2rem
            color #666
            font-size .26rem
        .button-list
            padding .1rem .6rem .1rem .1rem
            overflow hidden
            .button-wrapper
                float left
                width 33.33%
                .button
                    margin .1rem
                    padding .1rem 0
                    text-align center
                    border .02rem solid #ccc
                    border-radius .06rem
        .item-list
            .item
                line-height .76rem
                padding-left .2rem

</style>
